baptism of fire vs difficulty

baptism of fire

noun
  • Martyrdom by immolation. 

  • Tribulation endured as spiritual discipline. 

  • The gift of the Holy Spirit. 

  • The first experience of a severe ordeal, especially a first experience of military combat 

difficulty

noun
  • Physical danger from the environment, especially with risk of drowning 

  • An obstacle that hinders achievement of a goal. 

  • The state of being difficult, or hard to do. 

  • An objection. 

  • An awkward situation or quarrel. 

  • That which cannot be easily understood or believed. 

How often have the words baptism of fire and difficulty occurred in a corpus of books? (source: Google Ngram Viewer )